9560 IPv4 packets in IPv6 ethernet frames panic debug builds
Reviewed by: Jorge Schrauwen <jorge@blackdot.be>

*** 1787,1798 ****
                  /*
                   * Do src based fanout if below tunable is set to B_TRUE or
                   * when mac_ip_hdr_length_v6() fails because of malformed
                   * packets or because mblks need to be concatenated using
                   * pullupmsg().
                   */
!                 if (!mac_ip_hdr_length_v6(ip6h, mp->b_wptr, &hdr_len, &nexthdr,
                      NULL)) {
                          goto src_dst_based_fanout;
                  }
          } else {
                  hdr_len = IPH_HDR_LENGTH(ipha);
--- 1787,1801 ----
                  /*
                   * Do src based fanout if below tunable is set to B_TRUE or
                   * when mac_ip_hdr_length_v6() fails because of malformed
                   * packets or because mblks need to be concatenated using
                   * pullupmsg().
+                  *
+                  * Perform a version check to prevent parsing weirdness...
                   */
!                 if (IPH_HDR_VERSION(ip6h) != IPV6_VERSION ||
!                     !mac_ip_hdr_length_v6(ip6h, mp->b_wptr, &hdr_len, &nexthdr,
                      NULL)) {
                          goto src_dst_based_fanout;
                  }
          } else {
                  hdr_len = IPH_HDR_LENGTH(ipha);